1. Field of the Invention
The present invention relates to an image processing technology, particularly to a reconfigurable image processor capable of realizing two types of image processing modes by using a single set of hardware and the application architecture thereof.
2. Description of the Prior Art
Nowadays, digital imaging is widely applied in diverse fields and electronic products. For example, digital cameras are the commonest ways of generating digital images. Generally speaking, digital cameras support dual-mode functionalities: preview mode and capture mode. In the capture mode, the display module rapidly displays preview images, thus needing real-time image display at reduced resolution. The preview mode is designed to support digital cameras in photographing video information. On the contrary, the capture mode is designed to capture high-resolution images, thus demanding high quality. As high-quality images are stored in the memory, processing of the images are relatively not real-time.
Nowadays, image processors for digital cameras exist in two types. The first type is a digital signal processor (DSP) having a specific preview engine realized through integrated circuits (ICs). By combining two sets of hardware circuits into an IC, data flow is directly output to the display module to rapidly display preview images, after being processed by the preview engine in the preview mode. In this way, the data flow is not processed by a digital signal processor. On the contrary, in the capture mode, data flow is processed by the digital signal processor and stored in the memory, such that data flow is not processed by the preview engine. The advantage of the latter is: algorithms can be arbitrarily changed during image capture because of the availability of a digital signal processor, making it highly flexible. However, a drawback exists because a different set of hardware is required for the preview mode and the capture mode, and a digital signal processor is needed in the capture mode, thus slowing down processing.
The second type of image processors is designed as application specific integrated circuits (ASIC). The advantage is: image-processing capability is strong because the entire image processing process is realized by specific hardware. However, a drawback exists because the replacement of algorithms inside the ASIC is not possible, causing unsatisfactory flexibility. Considering that hardware design should take real-time processing and high-flexibility into account, optimal image processing is difficult to be realized, often causing excessive investments in hardware.